Process for the manufacture of sulphuric acid



Feb. '3, 1925. 1,525,382

w. FRANCK PROCESS FOR THE MANUFACTURE OF SULPHURIC ACID Filed July 8, 1924 lmnunu Fig.1

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Patented Feb. 3, 1925.

UNITED STATES PATENT o r-ical- OF SULFUR-AKTIENGESELLSCHAFT, OF ZURICH, SWITZERLAND,

0G SWITZERLAND.

A CORPORATION IROCESS FOR THE MANUFACTURE OF SULPHUR-1C ACID.

Application filed July 8,

To all whom it may concern:

Be it known that I, WILHIQLM FRANCK, a citizen of Germany residing at Mannheim -Wohlgelegen, Germany, have invented certain new and useful Improvements in the Processes for the Manufacture of Sulphuric Acid, of which the following is a specification. I

.In the ordinary process for the manufacture of sulphuric acid in the leaden chamber rocess the usual apparatus comprises a ay-Lussac tower for the recovery of the nitrogen oxides, and a Glover tower which is designed on the one hand to effect the concentration of the chamber acid in combination with the cooling of the hot roasting gases, and on the other hand to effect the de-nitration of the nitrogen compounds produced in the Gay-Lussac tower.

These two towers have hitherto usually been filled with acid-proof filling-materials such as for instance coke, acid-proof stoneware, etc. I have now discovered that all the towers required] for the manufacture of sulphuric acid according'to the chamber process, may be used without containing filling materials, if the acid is supplied to the towers in a sufiiciently fine state of subdivision, for instance, by means of spraying nozzles.

The introduction of the finely subdivided acid through the spraying nozzles may be effected advantageously by giving the acid under pressure whilst passing through the nozzle a rotating movement, thus causing it to leave the exit of the nozzle in the form of a fine mist.

The accompanying drawing shows by way of illustration a type of nozzle such as is used with advanta e for introducing the acid in a sufficiently ne subdivision according to my new process.

Fig. 1 shows a nozzle in cross section,

Fig. 2 the external case of the nozzle with the exit opening, Fig. 3 the fitting by which the acid is caused to rotate.

In the various figures identical constructional devices are numbered in the same way.

In detail, 1 is the outer shell of the nozzle, which at 2 carries a thread to be screwed. into the pipe lifting up the acid and at 3 a narrow aperture through which the acid 1924. Serial No. 724,902.

is ejected and which is advantageously conically enlarged towards the outside. 4 signifies a spindle placed into the shell of the nozzle having in its lower part 5 a screw shaped thread of high pitch.

[The casing of the nozzle. and also the spindle consist of acid-proof material for instance of hard lead. i"

From two to four nozzles of this kind placed preferably in the top part for example in the ceiling of a- Glover tower. are sufiicient for the irrigation.

The nozzles work as follows:

The acid after being lifted, .for example, by a centrifugal pump enters the nozzle with a pressure of 2-3 atmospheres through a lead pipe screwed in at 2, is given a rotating movement by the threads of the screw 5 and leaves the nozzles through the aperture 3 in form of spraying cone consisting of minute drops. With the above described improved manner of working neither the formation of the sulphuric acid nor the recovery of the gaseous nitrogen compounds are injuriously affected, whereas on the other hand various advantages are gained.

When treating pyrites of pulverulent consistency it is a common experience that, notwithstanding the use of dust chambers, ac-

cumulations of slime frequently occur in the Glover tower, and these accumulations of slimes must be removed by washing out the tower, thereby entailing the drawback of having to stop the working of the tower for this purpose. The said accumulations of slime which may also rise through other circumstances, for instance, by the presence of aluminium sulphates and iron sul hates, sometimes cause the formation 0 hard crusts which produces a choking of the interstices of the filling of the tower which must then be cleared out and freshly filled.

A further great disadvantage of using filling materials in. the towers, consists in this that such fillings cause a considerable loss of draughtwhich is trouble likely to be increased by the occurrence of an accumulation of slime and will then lead to undesirable stoppages of the working.

According to the present invention all those drawbacks are avoided and further more special advantages are obtained.

Since filling materials are dispensed with in the towers and solely a stone lining is required for protecting the leaden casing of the towers, the construction of the towers is extremely simplified and cheapened, because on bringing a tower into operation, the tower becomes very quickly warmed up in consequence of its low heat capacity, and consequently the concentrating action comes Veg? quicklv into operation.

lhe conditions of the'entire system of chambers as regards draught are very much more favourable since the full cross-sectional areas of the towers is available. The velocity with which the reaction gases travel through the towers is correspondingly low. This is an advantage for the reactions which take place in the towers and which require more or less time. Choking of the towers reaiasee and consequent stoppage of the working are effectively prevented.

The present application is in part a continuation of my copending case 637,361 filed May 7, 1923.

I claim:

In the lead chamber process of making sulphuric acid, the step of spraying acid containing nitrosyl sulphuric acid under forced pressure in the form of a fine mist in a downward direction into a Glover tower containing no filling material.

In testimony whereof I afl'ix my signature in presence of two Witnesses DR. WILHELM FRANCK.

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